1. Field of Invention
This invention relates generally to hunting bullets and more particularly to hollow point bullets.
2. Description of the Related Art
Hunting bullets are generally small caliber, i.e. less than 0.50 caliber. They generally have a hollow point or soft metal nose portion to increase expansion of the bullet upon impact with animal tissue in order to achieve increased energy adsorption within the target animal's body. Lead hollow point bullets have a significant drawback for use in hunting applications. They tend to upset and expand greatly within a short penetration distance and are thus not suitable for deep penetration. This is particularly true where the bullet hits a bone during passage into the animal. Hunters often aim for the shoulder area of the target animal in order to minimize the chance of the animal escaping after it has been shot and because the vital organs of the animal are in the same general area of the animal as the shoulder.
Expansion of the bullet is desirable to slow the bullet and transfer more energy to the target during passage through soft animal tissue. If the bullet does not expand significantly and does not hit a bone or vital organ, it may pass through the animal without killing the animal or stopping the animal. For the bullet to successfully pass through animal bone and still do damage to vital organs, it is necessary that the bullet have density, sufficient structural integrity and retained weight.
One hunting bullet which addresses some of the above needs is that disclosed in our prior U.S. Pat. No. 5,127,332, which is incorporated by reference in its entirety herein. The patent discloses a unitary metal body of generally H shaped longitudinal cross section with an empty hollow point in front and a rear cavity filled with a dense material such as lead. The rear cavity was closed by a disk to seal the lead from the environment. This bullet has several advantages and disadvantage. One advantage is that it has good weight retention due to the lead being confined to the rear cavity so the bullet does not lose a significant part of its weight if the petals in the front break off during penetrations of the target, since the front hollow point portion of the bullet is relatively light in comparison to the dense solid rear portion of the bullet. Another advantage is that the forward part of the side walls of the rear cavity of the bullet tend to bulge due to the forward inertia and kinetic energy of the heavy lead core during the rapid deceleration upon impact. The bulge helps in making a larger diameter wound channel, but reduces the depth of penetration. The disadvantage of this bullet is that it has been found to break apart with failure initiated at the bulge when it hits heavy bones at near muzzle velocity.
An improvement is needed in order to achieve the advantages of the bullet of our prior U.S. Pat. No. 5,127,332 without the disadvantage.